I have a relative who has just purchased his first Volvo (1991 940 2.0 SE Estate Auto with 135000 miles) and I'm a Saab man usually so I'm doing my best to assist him with it though I'm not a Volvo expert whatsoever! The car needs a few jobs doing that I was wondering if you guys could assist with. Firstly the gearbox light (overdrive light) keeps coming on and off of its own free will and the switch on the side of the auto gearbox shifte doesnt turn it on or off. I've read theres a relay for it but I'm not sure where....where could this fault be coming from and what can I check/do before I start replacing anything. There is no history of when the cambelt/timing belt was last changed so what is the change period (miles and years)and what kind of job is changing them with the tensioner as well as they are cheap to buy so may as well do both at once. It hasnt been serviced in a while what things apart from the obvious (oil, air, spark plugs replaced) whould be done (does diff oil need changing and if so what type does it require and how easy is the diff oil to change, whats the fuel filter like to change) And just lastly what kind of a job would changing the discs (rotors to you guys in the US) and and pads all round be and is there anything to bare in mind or special tools required.

Many Thanks for your time